Wireless communication devices, such as cellular telephones, are becoming increasingly popular. As is well known, cellular telephones communicate with a cellular communication network via cell sites which are located throughout a geographic serving area and which contain the elements required for wireless communication (e.g. radios and antennas). Each cell site serves a geographic area, called a cell. One of the major advantages of the use of a cellular telephone is mobility. That is, a cellular telephone user may continue to use a cellular telephone as the user travels within the geographic area served by the cellular communication network. As the cellular telephone moves from one cell to another, the call is "handed off" from one cell site to another cell site. Such mobility management of cellular telephones is well known in the art and is effective for providing continuous voice communications as the cellular telephone travels within the geographic serving area of the wireless communication network.
Wireless devices other than cellular telephones are also becoming popular. For example, wireless modems are available which allow mobile computing devices to transmit and receive data via a wireless communication network. Such mobile computing devices can receive packet data via packet data networks such as the Internet using the Internet Protocol (IP) for data communication. However, mobility management for such mobile computing devices presents a problem because IP was originally developed with the assumption that devices would be connected to the network at fixed locations. As such, a device would be assigned a unique IP address, which would define the device's physical connection to the network. Since a mobile computing device is not permanently connected to the network at any single point, an IP address associated with the mobile computing device does not define the device's physical connection to the network, thus violating an important assumption of IP addresses. Various techniques have been developed for mobility management as it relates to these mobile computing devices. One such technique is described in U.S. Pat. No. 5,159,592 which uses a nameserver and pseudo-IP addresses to associate fixed names of mobile units with the pseudo-IP addresses. Even though the pseudo-IP address may change, the current pseudo-IP address of a mobile unit can be determined by looking up the fixed name in the nameserver. A technique called tunneling is described in U.S. Pat. No. 5,325,362 which uses special routers to store current locations of mobile units in tables. When a router receives a packet for a mobile unit, the packet is forwarded, or tunneled, to the appropriate current location. U.S. Pat. No. 5,708,655 describes the assignment of temporary IP addresses to mobile units such that the mobile unit can provide the temporary IP address to another computer to effectuate the transfer of data between that computer and the mobile unit. These techniques provide some level of mobility management for mobile computing devices.
Currently there are devices, referred to herein as wireless voice and data devices, which combine the voice functionality of wireless cellular telephones with the data functionality of mobile computing devices. For example, AT&T Corp.'s PocketNet telephone combines a wireless cellular telephone with a mobile computing device. Such a device can be used to place voice telephone calls, and can also be used to communicate packet data via the Internet. For example, although somewhat limited, the PocketNet telephone is capable of browsing the World Wide Web (WWW) using its data functionality. Although these wireless voice and data devices are capable of combining the features of a cellular telephone and a mobile computing device, service providers have not taken advantage of the integration of these different services. Currently, voice and data services are provided separately by wireless service providers, and there is little, if any, interaction between the two operating modes. As a result of this separation of the voice and data functionality, the full benefits of such devices have yet to be realized.